Clinical investigations of halothane and isoflurane for induction and maintenance of foal anesthesia.

This study conducts a comparative analysis of the effects of two anesthetic drugs (halothane and isoflurane) on young horses, or foals. The research suggests both anesthetics are safe for use in foals, with relatively minor variations in effects, such as the speed of induction and recovery, or possible impacts on heart rate.

Objective and Methodology

• The study was conducted to compare the clinical anesthetic management of foals using two types of anesthetic drugs, halothane and isoflurane.
• Fifty-eight foals were divided into two equal groups for the investigation, with 30 administered halothane and 28 given isoflurane.
• Measurements were taken of features such as the speed of the anesthetic’s induction and recovery, the quality of these processes, and any biochemical changes in venous blood samples before and after anesthesia.

Findings and Interpretations

• The study found no significant differences in the demographics of the two groups (meaning, age, gender, weight, breed, etc., of the foals were statistically similar).
• The results of blood tests before and after the administration of the anesthetics showed minimal, clinically unimportant changes, suggesting that neither agent significantly altered foal health.
• Similarly to adult horses, foals exhibited an increased PaCO2 (partial pressure of carbon dioxide) level when under anesthesia. However, there was no detectable difference in the magnitude of this increase between the two anesthetics.
• Anesthesia induction and recovery was most rapid with isoflurane, although the quality of these processes was deemed acceptable for both drugs.
• Heart rate during isoflurane anesthesia was not significantly different from awake or conscious conditions. However, during halothane anesthesia, the heart rate was notably lower than control, except at the 91-120 minutes duration mark.

Conclusion and Implications

• The results of this investigation support the premise that foals can safely and reliably be anesthetized with either halothane or isoflurane.
• Though there were minor differences observed, such as isoflurane’s speedier induction and recovery and halothane’s temporary decrease in heart rate, both anesthetic agents were found to be effective without causing harm to the foals.